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Microscopy Research and Technique Jan 2024Diabetic retinopathy (DR) is a prevalent cause of global visual impairment, contributing to approximately 4.8% of blindness cases worldwide as reported by the World...
Diabetic retinopathy (DR) is a prevalent cause of global visual impairment, contributing to approximately 4.8% of blindness cases worldwide as reported by the World Health Organization (WHO). The condition is characterized by pathological abnormalities in the retinal layer, including microaneurysms, vitreous hemorrhages, and exudates. Microscopic analysis of retinal images is crucial in diagnosing and treating DR. This article proposes a novel method for early DR screening using segmentation and unsupervised learning techniques. The approach integrates a neural network energy-based model into the Fuzzy C-Means (FCM) algorithm to enhance convergence criteria, aiming to improve the accuracy and efficiency of automated DR screening tools. The evaluation of results includes the primary dataset from the Shiva Netralaya Centre, IDRiD, and DIARETDB1. The performance of the proposed method is compared against FCM, EFCM, FLICM, and M-FLICM techniques, utilizing metrics such as accuracy in noiseless and noisy conditions and average execution time. The results showcase auspicious performance on both primary and secondary datasets, achieving accuracy rates of 99.03% in noiseless conditions and 93.13% in noisy images, with an average execution time of 16.1 s. The proposed method holds significant potential in medical image analysis and could pave the way for future advancements in automated DR diagnosis and management. RESEARCH HIGHLIGHTS: A novel approach is proposed in the article, integrating a neural network energy-based model into the FCM algorithm to enhance the convergence criteria and the accuracy of automated DR screening tools. By leveraging the microscopic characteristics of retinal images, the proposed method significantly improves the accuracy of lesion segmentation, facilitating early detection and monitoring of DR. The evaluation of the method's performance includes primary datasets from reputable sources such as the Shiva Netralaya Centre, IDRiD, and DIARETDB1, demonstrating its effectiveness in comparison to other techniques (FCM, EFCM, FLICM, and M-FLICM) in terms of accuracy in both noiseless and noisy conditions. It achieves impressive accuracy rates of 99.03% in noiseless conditions and 93.13% in noisy images, with an average execution time of 16.1 s.
Topics: Humans; Diabetic Retinopathy; Image Interpretation, Computer-Assisted; Algorithms; Retina; Cluster Analysis; Diabetes Mellitus
PubMed: 37681440
DOI: 10.1002/jemt.24413 -
Ophthalmology. Retina Feb 2024Microaneurysms (MAs) have distinct, oval-shaped, hyperreflective walls on structural OCT, and inconsistent flow signal in the lumen with OCT angiography (OCTA). Their...
PURPOSE
Microaneurysms (MAs) have distinct, oval-shaped, hyperreflective walls on structural OCT, and inconsistent flow signal in the lumen with OCT angiography (OCTA). Their relationship to regional macular edema in diabetic retinopathy (DR) has not been quantitatively explored.
DESIGN
Retrospective, cross-sectional study.
PARTICIPANTS
A total of 99 participants, including 23 with mild, nonproliferative DR (NPDR), 25 with moderate NPDR, 34 with severe NPDR, and 17 with proliferative DR.
METHODS
We obtained 3 × 3-mm scans with a commercial device (Solix, Visionix/Optovue) in 99 patients with DR. Trained graders manually identified MAs and their location relative to the anatomic layers from cross-sectional OCT. Microaneurysms were first classified as perfused if flow signal was present in the OCTA channel. Then, perfused MAs were further classified into fully and partially perfused MAs based on the flow characteristics in en face OCTA. The presence of retinal fluid based on OCT near MAs was compared between perfused and nonperfused types. We also compared OCT-based MA detection to fundus photography (FP)- and fluorescein angiography (FA)-based detection.
MAIN OUTCOME MEASURES
OCT-identified MAs can be classified according to colocalized OCTA flow signal into fully perfused, partially perfused, and nonperfused types. Fully perfused MAs may be more likely to be associated with diabetic macular edema (DME) than those without flow.
RESULTS
We identified 308 MAs (166 fully perfused, 88 partially perfused, 54 nonperfused) in 42 eyes using OCT and OCTA. Nearly half of the MAs identified in this study straddle the inner nuclear layer and outer plexiform layer. Compared with partially perfused and nonperfused MAs, fully perfused MAs were more likely to be associated with local retinal fluid. The associated fluid volumes were larger with fully perfused MAs compared with other types. OCT/OCTA detected all MAs found on FP. Although not all MAs seen with FA were identified with OCT, some MAs seen with OCT were not visible with FA or FP.
CONCLUSIONS
OCT-identified MAs with colocalized flow on OCTA are more likely to be associated with DME than those without flow.
FINANCIAL DISCLOSURE(S)
Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Topics: Humans; Diabetic Retinopathy; Retinal Vessels; Microaneurysm; Cross-Sectional Studies; Macular Edema; Retrospective Studies; Tomography, Optical Coherence; Fluorescein Angiography; Retina
PubMed: 37673397
DOI: 10.1016/j.oret.2023.08.019 -
BMJ Case Reports Sep 2023Neurofibromatosis type 1 (NF1) is known to cause vascular complications including stenotic and aneurysmal disease. Here, we report a case of a woman in her early 20s,...
Neurofibromatosis type 1 (NF1) is known to cause vascular complications including stenotic and aneurysmal disease. Here, we report a case of a woman in her early 20s, who presented with unilateral facial nerve palsy and hypertensive crisis, and was later found to have multiple bilateral intrarenal microaneurysms along with classic cutaneous manifestations of NF1. A causal relationship between the pathophysiology of NF1 and the development of renal artery microaneurysm and hypertension is proposed in this case report.
Topics: Female; Humans; Neurofibromatosis 1; Hypertension; Cardiovascular Diseases; Bell Palsy; Facial Paralysis
PubMed: 37669821
DOI: 10.1136/bcr-2022-254012 -
Clinical Ophthalmology (Auckland, N.Z.) 2023To evaluate the agreement between conventional fundus photography (CFP) and multicolor fundus imaging (MFI) for the detection of lesions of diabetic retinopathy (DR) and...
PURPOSE
To evaluate the agreement between conventional fundus photography (CFP) and multicolor fundus imaging (MFI) for the detection of lesions of diabetic retinopathy (DR) and retinal vein occlusion (RVO).
METHODS
Cross-sectional analysis of eyes with DR or RVO who underwent CFP and MFI. All images were independently analyzed by two observers (O1 and O2), and the evaluated lesions were classified as "present" or "absent". Then, a paired comparison between both exams of the same eye was performed, to assess which made it easier to detect the lesions.
RESULTS
Considering DR, the agreement was substantial for cotton wool spots and photocoagulation scars for both observers (O1: =0.75 and =0.67; O2: =0.71 and =0.64, respectively) and for hard exudates for O1 (=0.80). These lesions were detected more frequently on MFI. Regarding RVO, the agreement was considered substantial for venous sheathing by O1 (=0.64) and moderate for optociliary shunts by O2 (=0.60). Optociliary shunts were detected more frequently in CPF by both observers and venous sheathing on MFI by O1. For microaneurysms, retinal hemorrhages, retinal neovascularization, and proliferative membranes, in DR, and retinal hemorrhages, venous engorgement, and retinal neovascularization in RVO, the agreement was almost perfect (>0.82). In the paired analysis, both observers considered that, in DR, microaneurysms and retinal hemorrhages were easier to detect on CFP and that retinal neovascularization, cotton wool spots, and photocoagulation scars were easier to identify on MFI. Regarding RVO, optocilliary shunts were easier to identify on CFP and venous engorgement on MFI.
CONCLUSION
The agreement of MFI and CFP was substantial to almost perfect for most lesions. MFI seems better to detect cotton wool spots and photocoagulations scars in DR and venous sheathing in RVO. Optocilliary shunts seem easier to detect on CFP.
PubMed: 37641738
DOI: 10.2147/OPTH.S414603 -
Indian Journal of Ophthalmology Aug 2023To characterize the relationship between diabetic macular ischemia (DMI) delineated by optical coherence tomography angiography (OCTA) and microaneurysms (MAs)...
PURPOSE
To characterize the relationship between diabetic macular ischemia (DMI) delineated by optical coherence tomography angiography (OCTA) and microaneurysms (MAs) identified by fundus fluorescein angiography (FFA).
METHODS
Patients with diabetic retinopathy (DR) who underwent OCTA and FFA were retrospectively identified. FFA images were cropped and aligned with their respective OCTA images using i2k Align Retina software (Dual-Align, Clifton Park, NY, USA). Foveal avascular zone (FAZ) and ischemic areas were manually delineated on OCTA images, and MAs were marked on the corresponding FFA images before overlaying paired scans for analysis (ImageJ; National Institutes of Health, Bethesda, MD, USA).
RESULTS
Twenty-eight eyes of 20 patients were included. The average number of MAs identified in cropped FFA images was 127 ± 42. More DMI was noted in the superficial capillary plexus (SCP; 36 ± 13%) compared to the deep capillary plexus (DCP; 28 ± 14%, P < 0.001). Similarly, more MAs were associated with ischemic areas in SCP compared to DCP (92.0 ± 35.0 vs. 76.8 ± 36.5, P < 0.001). Most MAs bordered ischemic areas; fewer than 10% localized inside these regions. As DMI area increased, so did associated MAs (SCP: r = 0.695, P < 0.001; DCP: r = 0.726, P < 0.001). Density of MAs surrounding FAZ (7.7 ± 6.0 MAs/mm) was similar to other DMI areas (SCP: 7.0 ± 4.0 MAs/mm, P = 0.478; DCP: 9.2 ± 10.9 MAs/mm, P = 0.394).
CONCLUSION
MAs identified in FFA strongly associate with, and border areas of, DMI delineated by OCTA. Although more MAs are localized to SCP ischemia, the concentration of MAs associated with DCP ischemia is greater. By contrast, few MAs are present inside low-flow regions, likely because capillary loss is associated with their regression.
Topics: Humans; Fluorescein Angiography; Retinal Vessels; Retrospective Studies; Tomography, Optical Coherence; Microaneurysm; Fundus Oculi; Visual Acuity; Diabetic Retinopathy; Diabetes Mellitus
PubMed: 37530285
DOI: 10.4103/IJO.IJO_3155_22 -
Ophthalmology. Retina Dec 2023To evaluate the association of microvascular lesions on ultrawidefield (UWF) color fundus (CF) images with retinal nonperfusion (RNP) up to the midperiphery on...
PURPOSE
To evaluate the association of microvascular lesions on ultrawidefield (UWF) color fundus (CF) images with retinal nonperfusion (RNP) up to the midperiphery on single-capture widefield (WF) OCT angiography (OCTA) in patients with diabetic retinopathy (DR).
DESIGN
Cross-sectional study.
SUBJECTS
Seventy-five eyes of 50 patients with mild to severe nonproliferative DR (NPDR) and proliferative DR (PDR) were included in this analysis.
METHODS
ETDRS level and presence of predominantly peripheral lesions (PPLs) were assessed on UWF-CF images acquired with a Zeiss Clarus 700. Single-capture 65°-WF-OCTA was performed using a PlexElite prototype (Carl Zeiss Meditec, Inc.). A custom grid consisting of a central ETDRS grid extended by 2 rings reaching up to the midperiphery was overlaid to subdivide retinal areas visible on WF-OCTA en face images. Retinal nonperfusion was measured in each area and in total. Nonperfusion index (NPI) was calculated from total RNP. On UWF-CF images, the number of microaneurysms, hemorrhages, neovascularizations, and areas with intraretinal microvascular abnormalities (IRMAs) were evaluated using the same grid.
MAIN OUTCOME MEASURES
Association of diabetic lesions with RNP was calculated using Spearman correlations (r).
RESULTS
Median RNP on WF-OCTA was 0 mm (0-0.9), 4.9 mm (1.9-5.4), 23.4 mm (17.8-37), and 68.4 mm (40.8-91.7) in mild, moderate, and severe NPDR and PDR, respectively. We found a statistically significant correlation (P < 0.01) of overall RNP (r = 0.96,) and NPI (r = 0.97) on WF-OCTA with ETDRS level. Number of grid-fields affected by IRMAs on CF images was highly associated with NPI (r = 0.86, P < 0.01). Intraretinal microvascular abnormalities and RNPs had similar topographic distributions with high correlations in affected areas. Eyes with PPLs (n = 43 eyes, 57%) on CF images had a significantly higher NPI (P = 0.014) than eyes without PPLs.
CONCLUSION
The combination of UWF-CF imaging and single-capture WF-OCTA allows precise and noninvasive analysis of the retinal vasculature up to the midperiphery in patients with DR. The presence and extent of IRMAs on CF images may serve as an indicator for underlying RNP, which is more pronounced in eyes with PPLs.
FINANCIAL DISCLOSURE(S)
Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Topics: Humans; Cross-Sectional Studies; Fluorescein Angiography; Retina; Diabetic Retinopathy; Multimodal Imaging; Diabetes Mellitus
PubMed: 37517798
DOI: 10.1016/j.oret.2023.07.020 -
Medicina (Kaunas, Lithuania) Jul 2023: This study aimed to elucidate the role of laser photocoagulation therapy in the treatment of diabetic macular edema (DME) as an alternative to, or in conjunction with,... (Review)
Review
: This study aimed to elucidate the role of laser photocoagulation therapy in the treatment of diabetic macular edema (DME) as an alternative to, or in conjunction with, the first-line treatment, anti-vascular endothelial growth factor (VEGF). : A comprehensive literature search to identify studies that evaluated the efficacy of laser photocoagulation therapy in the management of DME was performed. The relevant findings of the efficacy of focal/grid laser therapy from data in randomized, controlled trials were synthesized, and the potential of new laser technologies, such as navigated laser systems, pattern scan lasers, and subthreshold lasers, was explored. The usefulness of multimodal imaging-guided laser therapy was also evaluated, with a focus on the potential contribution to anti-VEGF therapy. : Focal laser photocoagulation targeting microaneurysms remains an effective therapeutic approach to chronic refractory edema, despite the widespread use of anti-VEGF therapy. To achieve the best possible treatment outcomes, precise identification of microaneurysms is essential. This requires the use of multimodal imaging-guided, highly accurate, minimally invasive coagulation techniques. Subthreshold laser therapy can also reduce the frequency of anti-VEGF injections and minimize treatment burden. : Further studies are needed to determine the optimal timing and settings for laser photocoagulation therapy and the potential of new laser technologies in the management of DME. Nevertheless, laser photocoagulation therapy plays an important role in the management of DME, in conjunction with anti-VEGF therapy.
Topics: Humans; Macular Edema; Diabetic Retinopathy; Microaneurysm; Laser Coagulation; Laser Therapy; Treatment Outcome; Diabetes Mellitus
PubMed: 37512130
DOI: 10.3390/medicina59071319 -
Orphanet Journal of Rare Diseases Jul 2023To determine whether the rare NLRP3-Associated Autoinflammatory Disease (NLRP3-AID) is associated with retinal changes and to assess the ocular involvement.
PURPOSE
To determine whether the rare NLRP3-Associated Autoinflammatory Disease (NLRP3-AID) is associated with retinal changes and to assess the ocular involvement.
METHODS
A retrospective cohort study of 20 patients(40 eyes) diagnosed with rare NLRP3-AID at Peking Union Medical College Hospital, from April 2015 to August 2022. Patients underwent a comprehensive ophthalmological examination, including visual acuity, intraocular pressure examination, slit-lamp examination, fundus photography, optical coherence tomography(OCT), and fluorescence angiography (FA). Some patients also underwent optical coherence tomography angiography (OCTA).
RESULTS
This study analyzed 40 eyes of 20 patients (11 [55.0%] male; median age, 25.0 years [range, 12-52 years]) and 13 patients (26 eyes, 65%) demonstrated ocular involvement. The most common ophthalmologic manifestation was conjunctivitis (22 eyes, 84.6%), followed by papilledema (14 eyes, 53.8%), retinopathy (10 eyes, 38.5%), optic atrophy (6 eyes, 23.1%), uveitis (4 eyes, 15.4%), reduced pupil light reflex (3 eyes, 11.5%) and cataracts (2 eyes, 7.7%). Ocular involvement was bilateral in 11 patients (55.0%). Five kinds of retinal lesions were seen in 5 patients (10 eyes, 25%) with NLRP3-AID, including peripheral retinal vascular leakage, microaneurysms, macular ischemia, macular epiretinal membrane formation and drusen.
CONCLUSIONS
Peripheral retinal vascular leakage, macular ischemia, microaneurysms and drusen are newly identified retinal findings in patients with NLRP3-AID, which suggests the importance of detailed retinal examination in these patients.
Topics: Humans; Male; Adult; Female; NLR Family, Pyrin Domain-Containing 3 Protein; Retrospective Studies; Microaneurysm; Retinal Diseases; Tomography, Optical Coherence; Ischemia; Hereditary Autoinflammatory Diseases
PubMed: 37480029
DOI: 10.1186/s13023-023-02815-1 -
Scientific Reports Jul 2023We investigated predictors of visual outcomes and injection interval in macular edema (ME) secondary to branch retinal vein occlusion (BRVO) treated with a...
We investigated predictors of visual outcomes and injection interval in macular edema (ME) secondary to branch retinal vein occlusion (BRVO) treated with a treat-and-extend (TAE) regimen. All 48 patients in a multicenter study were followed for 52 weeks and received three monthly intravitreal aflibercept injections before the TAE regimen, with treatment intervals adjusted by 4 weeks, up to a maximum of 16 weeks. Various laboratory biomarkers and optical coherence tomography parameters were evaluated. Patients were classified into the extension failure group if they had ≥ 1 treatment interval decreased due to an increase in the central macular thickness compared to the previous visit and 18 patients were assigned to this group. In multivariate logistic analyses, presence of microaneurysms and prominent middle limiting membrane (p-MLM) sign, increased initial external limiting membrane (ELM) disruption, and higher total cholesterol were correlated with inhibiting a sustained extension in the injection interval (P = 0.015, P = 0.032, P = 0.037, P = 0.009, respectively). Therefore, in the patients with ME secondary to BRVO with these risk factors, early consideration of frequent injection may improve treatment outcome.
Topics: Humans; Retinal Vein Occlusion; Angiogenesis Inhibitors; Macular Edema; Treatment Outcome; Intravitreal Injections; Tomography, Optical Coherence; Retrospective Studies
PubMed: 37474669
DOI: 10.1038/s41598-023-38955-4